[Haskell-beginners] :trace seems not to work in ghci

Hey, I have a program I want to debug in ghci because it crashes with an exception. So I do: Prelude> :l Main Ok, modules loaded: Main, PlotDisplay, PlotDiagram, ForexData. Prelude Main> :set -fbreak-on-exception Prelude Main> :trace main (...) Stopped at <exception thrown> _exception :: e = _ [<exception thrown>] Prelude Main> :hist Empty history. Perhaps you forgot to use :trace? [<exception thrown>] Prelude Main> :back no more logged breakpoints [<exception thrown>] Prelude Main> :force _exception _exception = GHC.Exception.SomeException (GHC.Exception.ErrorCall "Prelude.tail: empty list") What could be the reason why :hist/:back/:trace are not working? Thanks! Nathan